RTX 3080 Having a Meltdown

Report · Feb 15, 2021

Ok that's probably not the most descriptive title but hey, sounds fun doesn't it?

So I recently took delivery of a new PC in the hope it would solve some problems I'm having with playback on Premier Pro. Super laggy and sometimes unresponsive for a couple of minutes. I will admit that my knowledge of PC's is pretty limited. I just purchased this using a mixture of recommendations, and buying the most expensive thing I could afford.

Specs

CPU: Ryzen 9 3950X 16 Core

GRAPHICS: 10GB NVIDIA GEFORCE RTX 3080

RAM: 128GB Corsair VENGEANCE DDR4 3000MHz

OS AND PROGRAM M2 SSD: 1TB SAMSUNG 970 EVO PLUS M.2, PCIe NVMe (up to 3500MB/R, 3300MB/W)

STORAGE SSD: 2TB SEAGATE BARRACUDA 120 2.5" SSD, (up to 560MB/sR | 540MB/sW)

I've got Premier Pro (14.9) installed on my main OS drive which is an M2. However my project and video files are on the SSD.

Currently I'm editing a video that is a Macbook Pro Screen recording over a video that includes narration. And this is what task manager currently looks like. I'm particularly drawn to the Video Decoding chart.

As for the project, this is what the timeline looks like as well as samples from the video files. I'm currently using 1/8 resolution and hiding the track I am not working on in an attempt to press on.

Yes they are both effectively 4k recordings. But I didn't expect to be getting this much lag considering the power of this PC. But then again, I might be completely naive in thinking that. After some testing, I found out that it's primarily the screen recording (Window on the Left) that causes the decoding spikes. The video from the camera seems to be ok when running solo.

Any advice, tips, or general roasting would be greatly appreciated!

Cheers,

Matt

Report · Feb 15, 2021

1) Try to interpret that 51.72fps screen recording footage as 50fps. If not help, 2) Turn off hardware accelerated decoding in Preferences > Media. If not help, 3) Convert that VFR (variable framerate) footage into CFR (constant framerate) via Handbrake 3rd-party tool

Report · Feb 15, 2021

I've been meaning to try interpreting the footage on VFR. I rarely ever work with the stuff, but does that actually work? That would certainly be an easier way to deal with it.

Report · Feb 15, 2021

You have a great machine, so no worries there. But hopefully when you were getting advice you were informed about how important the type of media is that you work with. The media has a huge impact.

The H264 video codec is not optimized for editing. If it's high res, high bitrate, high framerate, that can all add to the difficulty in your computer decoding (playing) that type of footage. On a computer like that, you could probably push through a decent amount of H264 on its own, and your framerate isn't high, at least on the 25 FPS clip in the MOV container.

I think the problem starts with the addition of the other clip. When you add multiple video sources that are H264, that's twice the decoding the computer has to do. Even though your video card is assisting (as shown in your picture, it's maxing out the decoder portion of the card), you now have two H264 sources, and the second one is high framerate, and not only that it's variable framerate, which causes all kinds of issues for editing software, which likes a constant framerate.

Fixing the Variable Framerate (VFR) usually involves transcoding it in a software that can convert it to constant. Usually something like Handbrake or Shutter Encoder. If you don't need the audio from that file and you just need the video, sometimes you can just use Adobe Media Encoder. The resulting file would be a constant framerate, but things like audio drifting out of sync would get "burned in." -- As a note, VFR is common in screen capture or phone video where the device can't keep up with the recording so drops the framerate until it can catch up.

Addressing the H264 is about optimizing your media. The two ways to do that are two:

1) Transcode your media before working with it to an optimized codec, also called an intermediate codec. The most common of those are Quicktime ProRes, DNxHD/HR, or Cineform. (I usually use ProRes)

2) Make proxies into an optimized video codec. This is typically the route that I go because you can make proxies at any point during a project, and when the project is done you can delete them. I use the Quicktime ProRes Proxy Low/Med resolution presets right in Premiere for most situations. Note that creating proxies for VFR media is not recommended, as the proxy may not line up with the original clip so you don't get an accurate sense of what you're doing with editing.

Report · Feb 15, 2021

Yea I thought I was bad with PC knowledge, video codecs are a whole new level!

That's a massive help though. You've given me plenty of things to have a go at and explained it clearly. Cheers mate!

Report · Feb 15, 2021

Here are a couple resources for you!

Going deeper on video codecs so you can hopefully better understand the why behind some of these things: https://blog.frame.io/2017/02/15/choose-the-right-codec/

Another little wiki page on VFR: https://www.reddit.com/r/VideoEditing/wiki/faq/vfr